Upper Cretaceous deposits in the northwest of Saratov region, Part 2: Problems of chronostratigraphy and regional geological history

摘要

Problems of geochronological correlation are considered for the formations established in the study region with due account for data on the Mezino-Lapshinovka, Lokh and Teplovka sections studied earlier on the northwest of the Saratov region. New paleontological data are used to define more precisely stratigraphic ranges of some stratigraphic subdivisions, to consider correlation between standard and local zones established for different groups of fossils, and to suggest how the Upper Cretaceous regional scale of the East European platform can be improved. Considered in addition are paleogeographic environments in the study region during the Late Cretaceous epoch and principal stages of the regional geological evolution.